package day04;
import java.util.Scanner;
public class DoWhileDemo {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        int count = 0;
        for (int year=1900;year<=2023;year++){
            if ((year%4==0 && year%100!=0) || year%400==0){
                System.out.println(year+" ");
                count++;
                if (count%10==0){
                    System.out.println();
                }

            }
        }

        int sum = 0;
        int i = 1;
        while (i<=100){
            sum+=i;
            i++;
        }
        System.out.println("sum="+sum);

        System.out.println("请输入你想要的数");
        int num = scan.nextInt();
        if (num>0){
            System.out.println("+");
        }else if (num<0){
            System.out.println("-");
        }else{
            System.out.println("0");
        }

        System.out.println("请输入年份");
        int year = scan.nextInt();
        System.out.println("请输入月份");
        int month = scan.nextInt();
        int days = 0;
        switch(month){
            case 1:
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12:
                days=31;
                break;
            case 4:
            case 6:
            case 9:
            case 11:
                days=30;
                break;
            case 2:
                if ((year%4==0 && year%100!=0) || year%400==0){
                    days = 29;
                }else{
                    days = 28;
                }
        }
        System.out.println(year+"年份"+month+"月共"+days+"天");
    }
}
